<xr id="tab:Overview_of_the_Most_Widely_Used_Silver_Grades"/><!--(Table 2.11 )--> shows the typically available quality grades of silver. In certain economic areas, i.e. China, there are additional grades with varying amounts of impurities available on the market. In powder form silver is used for a wide variety of silver based composite contact materials. Different manufacturing processes result in different grades of Ag powder as shown in <xr id="tab:Quality_Criteria_of_Differently_Manufactured_Silver_Powders"/><!--Table 2.12-->. additional Additional properties of silver powders and their usage are described in chapter [[ Precious Metal Powders and Preparations#Precious_Metal_Powders|Precious Metal Powders ]] und [[Precious_Metal_Powders_and_Preparations|Table Different Types of Silver Powders.]]<!--(Tab. 8.1.)--> Semi-finished silver materials can easily be warm or cold formed and can be clad to the usual base materials(<xr id="fig:Strain hardening of Ag bei cold working"/> and <xr id="fig:Softening of Ag after annealing after different degrees"/>). For attachment of silver to contact carriermaterials welding of wire or profile cut-offs and brazing are most widely applied. Besides these mechanical processes such as wire insertion (wire staking) and the riveting (staking) of solid or composite contact rivets are used in the manufacture of contact components.

currents < 2 A ''(<xr id="tab:Application Examples and Forms of Supply for Silver and Silver Alloys"/>)<!--(Table 2.16)''-->. Electroplated silver coatings are widely used to reduce the contact resistance and improve the brazing behavior of other contact materials and components.

<figtable id="tab:Overview_of_the_Most_Widely_Used_Silver_Grades"><caption>'''<!--Table 2.1211: Quality Criteria -->Overview of Differently Manufactured the Most Widely Used Silver PowdersGrades'''</caption><table class="twocolortable"><tr><th><p class="s12">Designation</p></th><th><p class="s12">Composition minimum Ag [wt%]</p></th><th><p class="s12">Impurities</p><p class="s12">[ppm]</p></th><th><p class="s12">Notes on Usage</p></th></tr><tr><td><p class="s12">Spectroscopically</p><p class="s12">Pure Ag</p></td><td><p class="s11">99.999</p></td><td><p class="s11">Cu &lt; 3</p><p class="s11">Zn &lt; 1</p><p class="s11">Si &lt; 1</p><p class="s11">Ca &lt; 2</p><p class="s11">Fe &lt; 1</p><p class="s11">Mg &lt; 1</p><p class="s11">Cd &lt; 1</p></td><td><p class="s12">Sheets, strips, rods, wires for electronic applications</p></td></tr><tr><td><p class="s12">High Purity Ag, oxygen-free</p></td><td><p class="s11">99.995</p></td><td><p class="s11">Cu &lt; 30</p><p class="s11">Zn &lt; 2</p><p class="s11">Si &lt; 5</p><p class="s11">Ca &lt; 10</p><p class="s11">Fe &lt; 3</p><p class="s11">Mg &lt; 5</p><p class="s11">Cd &lt; 3</p></td><td><p class="s12">Ingots, bars, granulate for alloying purposes</p><p class="s12"></p></td></tr></table></figtable>

Fig<figtable id="tab:Quality_Criteria_of_Differently_Manufactured_Silver_Powders"><caption>'''<!--Table 2. 12:-->Quality Criteria of Differently Manufactured Silver Powders'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!colspan="2" |Impurities !Ag-Chem.46*!Ag-ES**!Ag-V***|-|Cu |ppm|< 100|< 300|< 300|-|Fe |ppm|< 50|< 100|< 100|-|Ni |ppm|< 50|< 50|< 50|-|Cd |ppm|||< 50|-|Zn |ppm|||< 10|-|Na + K + Mg + Ca |ppm|< 80|< 50|< 50|-|Ag CI |ppm|< 500|< 500|< 500|-|NO₃ |ppm|< 40|< 40||-|Nh₄CI |ppm|< 30|< 30||-!colspan="5" |Particle Size Distribution (screen analysis)|-|> 100 μm |%|0|0|0|-|< 100 bis > 63 μm |%|< 5|< 5|< 15|-|< 36 μm |%|< 80|< 90|< 75|-|Apparent Density |g/cm³|1.0 - 1.6|1.0 - 1.5|3 - 4|-|Tap Density |ml/100g|40 - 50|40 - 50|15 - 25|-!colspan="5" |Press/Sintering Behavior|-|Press Density |g/cm³|5.6 - 6.5|5.6 - 6.3|6.5 - 8.5|-|Sinter Density |g/cm³|> 9|> 9.3|> 8|-|Volume Shrinkage |%|> 34|> 35|> 0|-|Annealing Loss|%|< 2|< 0.1|< 0.1|}</figtable> <nowiki>*</nowiki> Manufactured by chemical precipitation <br /><nowiki>**</nowiki> Manufactured by electrolytic deposition <br /><nowiki>***</nowiki> Manufactured by atomizing of a melt  <div class="multiple-images"> <figure id="fig:Strain hardening of Ag bei cold working">[[File: Softening Strain hardening of Ag bei cold working.jpg|left|thumb|<caption>Strain hardening of Ag 99.95 - cold working</caption>]]</figure> <figure id="fig:Softening of Ag after annealing for 1 hr after different degrees of strain hardening">[[File:Softening of Ag after annealing after different degrees.jpg|rightleft|thumb|<caption>Softening of Ag 99.95 after annealing for 1 hr after different degrees of strain hardening</caption>]]</figure></div><div class="clear"></div>

To improve the physical and contact properties of fine silver , melt-metallurgical produced silver alloys are used ''(<xr id="tab:Physical Properties of Silver and Silver Alloys"/>)<!--(Table 2.13)''-->. By adding metal components , the mechanical properties such as hardness and tensile strength as well as typical contact properties such as erosion resistance, and resistance against material transfer in DC circuits are increased ''(<xr id="tab:Mechanical Properties of Silver and Silver Alloys"/>)<!--(Table 2.14)''-->. On the other hand however, other properties such as electrical conductivity and chemical corrosion resistance can be negatively impacted by alloying ''(Figs<xr id="fig:Influence of 1 10 atom of different alloying metals"/><!--(Fig. 2.47 )--> and <xr id="fig:Electrical resistivity p of AgCu alloys"/>)<!--(Fig. 2.48)-->. <figtable id="tab:Physical Properties of Silver and Silver Alloys"><caption>'''<!--Table 2.13:-->Physical Properties of Silver and Silver Alloys'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Density<br />[g/cm³]!Melting Point<br />or Range<br />[°C]!Electrical<br />Resistivity<br />[μΩ·cm]!Electrical<br />Conductivity<br />[MS/m]!Thermal<br />Conductivity<br />[W/mK]!Temp. Coefficient of<br />the Electr.Resistance<br />[10^-3/K]!Modulus of<br />Elasticity<br />[GPa]|-|Ag|99.95|10.5|961|1.67|60|419|4.1|80|-|AgNi0.15|99.85|10.5|960|1.72|58|414|4.0|82|-|AgCu3|97|10.4|900 - 938|1.92|52|385|3.2|85|-|AgCu5|95|10.4|910|1.96|51|380|3.0|85|-|AgCu10|90|10.3|870|2.0|50|335|2.8|85|-|AgCu28|72|10.0|779|2.08|48|325|2.7|92|-|Ag98CuNi<br />ARGODUR 27|98|10.4|940|1.92|52|385|3.5|85|-|AgCu24.5Ni0.5|75|10.0|805|2.20|45|330|2.7|92|-|Ag99.5NiMg<br />ARGODUR 32<br />Not heat treated|99.5|10.5|960|2.32|43|293|2.3|80|-|ARGODUR 32<br />Heat treated|99.5|10.5|960|2.32|43|293|2.1|80|}</figtable> <div class="multiple-images"> <figure id="fig:Influence of 1 10 atom of different alloying metals">[[File:Influence of 1 10 atom of different alloying metals.jpg|left|thumb|<caption>Influence of 1-10 atom% of different alloying metals on the electrical resistivity of silver</caption>]]</figure> <figure id="fig:Electrical resistivity p of AgCu alloys">[[File:Electrical resistivity p of AgCu alloys.jpg|left|thumb|<caption>Electrical resistivity p of AgCu alloys with 0-20 weight% Cu in the soft annealed and tempered stage a) Annealed and quenched b) Tempered at 280°C</caption>]]</figure></div><div class="clear"></div> <figtable id="tab:Mechanical Properties of Silver and Silver Alloys"><caption>'''<!--Table 2.14:-->Mechanical Properties of Silver and Silver Alloys'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></th><th><p class="s12">Hardness</p><p class="s12">Condition</p></th><th><p class="s12">Tensile Strength</p><p class="s12">R<span class="s31">m </span>[MPa]</p></th><th><p class="s12">Elongation A [%] min.</p></th><th><p class="s12">Vickers Hardness</p><p class="s12">HV 10</p></th></tr><tr><td><p class="s12">Ag</p></td><td><p class="s12">R 200</p><p class="s12">R 250</p><p class="s12">R 300</p><p class="s12">R 360</p></td><td><p class="s12">200 - 250</p><p class="s12">250 - 300</p><p class="s12">300 - 360</p><p class="s12">&gt; 360</p></td><td><p class="s12">30</p><p class="s12">8</p><p class="s12">3</p><p class="s12">2</p></td><td><p class="s12">30</p><p class="s12">60</p><p class="s12">80</p><p class="s12">90</p></td></tr><tr><td><p class="s12">AgNi0.15</p><p class="s12"></p></td><td><p class="s12">R 220</p><p class="s12">R 270</p><p class="s12">R 320</p><p class="s12">R 360</p></td><td><p class="s12">220 - 270</p><p class="s12">270 - 320</p><p class="s12">320 - 360</p><p class="s12">&gt; 360</p></td><td><p class="s12">25</p><p class="s12">6</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">40</p><p class="s12">70</p><p class="s12">85</p><p class="s12">100</p></td></tr><tr><td><p class="s12">AgCu3</p></td><td><p class="s12">R 250</p><p class="s12">R 330</p><p class="s12">R 400</p><p class="s12">R 470</p></td><td><p class="s12">250 - 330</p><p class="s12">330 - 400</p><p class="s12">400 - 470</p><p class="s12">&gt; 470</p></td><td><p class="s12">25</p><p class="s12">4</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">45</p><p class="s12">90</p><p class="s12">115</p><p class="s12">120</p></td></tr><tr><td><p class="s12">AgCu5</p></td><td><p class="s12">R 270</p><p class="s12">R 350</p><p class="s12">R 460</p><p class="s12">R 550</p></td><td><p class="s12">270 - 350</p><p class="s12">350 - 460</p><p class="s12">460 - 550</p><p class="s12">&gt; 550</p></td><td><p class="s12">20</p><p class="s12">4</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">55</p><p class="s12">90</p><p class="s12">115</p><p class="s12">135</p></td></tr><tr><td><p class="s12">AgCu10</p></td><td><p class="s12">R 280</p><p class="s12">R 370</p><p class="s12">R 470</p><p class="s12">R 570</p></td><td><p class="s12">280 - 370</p><p class="s12">370 - 470</p><p class="s12">470 - 570</p><p class="s12">&gt; 570</p></td><td><p class="s12">15</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">60</p><p class="s12">95</p><p class="s12">130</p><p class="s12">150</p></td></tr><tr><td><p class="s12">AgCu28</p></td><td><p class="s12">R 300</p><p class="s12">R 380</p><p class="s12">R 500</p><p class="s12">R 650</p></td><td><p class="s12">300 - 380</p><p class="s12">380 - 500</p><p class="s12">500 - 650</p><p class="s12">&gt; 650</p></td><td><p class="s12">10</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">90</p><p class="s12">120</p><p class="s12">140</p><p class="s12">160</p></td></tr><tr><td><p class="s12">Ag98CuNi</p><p class="s12">ARGODUR 27</p></td><td><p class="s12">R 250</p><p class="s12">R 310</p><p class="s12">R 400</p><p class="s12">R 450</p></td><td><p class="s12">250 - 310</p><p class="s12">310 - 400</p><p class="s12">400 - 450</p><p class="s12">&gt; 450</p></td><td><p class="s12">20</p><p class="s12">5</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">50</p><p class="s12">85</p><p class="s12">110</p><p class="s12">120</p></td></tr><tr><td><p class="s12">AgCu24,5Ni0,5</p></td><td><p class="s12">R 300</p><p class="s12">R 600</p></td><td><p class="s12">300 - 380</p><p class="s12">&gt; 600</p></td><td><p class="s12">10</p><p class="s12">1</p></td><td><p class="s12">105</p><p class="s12">180</p></td></tr><tr><td><p class="s12">Ag99,5NiMg</p><p class="s12">ARGODUR 32</p><p class="s12">Not heat treated</p></td><td><p class="s12">R 220</p><p class="s12">R 260</p><p class="s12">R 310</p><p class="s12">R 360</p></td><td><p class="s12">220</p><p class="s12">260</p><p class="s12">310</p><p class="s12">360</p></td><td><p class="s12">25</p><p class="s12">5</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">40</p><p class="s12">70</p><p class="s12">85</p><p class="s12">100</p></td></tr><tr><td><p class="s12">ARGODUR 32 Heat treated</p></td><td><p class="s12">R 400</p></td><td><p class="s12">400</p></td><td><p class="s12">2</p></td><td><p class="s12">130-170</p></td></tr></table></figtable>

Fine-Grain Silver (ARGODUR-Spezial) silver is defined as a silver alloy with an addition of 0.15 wt% of Nickelnickel. Silver and nickel are not soluble in each other in solid form. In liquid silver , only a small amount of nickel is soluble as the phase diagram ''illustrates (<xr id="fig:Phase diagram of silver nickel"/><!--(Fig. 2.51)'' illustrates-->). During solidification of the melt , this nickel addition gets finely dispersed in the silver matrix and eliminates the pronounce coarse grain growth after prolonged influence of elevated temperatures ''(Figs<xr id="fig:Coarse grain micro structure of Ag"/><!--(Fig. 2.49 )--> and <xr id="fig:Fine grain microstructure of AgNiO"/><!--(Fig. 2.50)''-->). <div class="multiple-images"> <figure id="fig:Coarse grain micro structure of Ag">[[File:Coarse grain micro structure of Ag.jpg|rightleft|thumb|<caption>Coarse grain micro structure of Ag 99.97 after 80% cold working and 1 hr annealing at 600°C</caption>]]</figure> <figure id="fig:Fine grain microstructure of AgNiO">[[File:Fine grain microstructure of AgNiO.jpg|left|thumb|<caption>Fine grain microstructure of AgNi0.15 after 80% cold working and 1 hr annealing at 600°C</caption>]]</figure> <figure id="fig:Phase diagram of silver nickel">[[File:Phase diagram of silver nickel.jpg|left|thumb|<caption>Phase diagram of silver nickel</caption>]]</figure></div><div class="clear"></div> Fine-grain Grain silver has almost the same chemical corrosion resistance as fine silver. Compared to pure silver , it exhibits a slightly increased hardness andtensile strength ''(<xr id="tab:Mechanical Properties of Silver and Silver Alloys"/><!--(Table 2.14)''-->). The electrical conductivity is just slightly decreased by this low nickel addition. Because of its significantly improved contact properties , fine grain silver has replaced pure silver in many applications.

Using copper as an alloying component increases the mechanical stability of silver significantly(<xr id="fig:Strain hardening of AgCu3 by cold working"/>, <xr id="fig:Softening of AgCu3 after annealing"/> and <xr id="fig:Strain hardening of AgCu5 by cold working"/>). The most important among the binary AgCu alloys is that of AgCu3, known in europe also under the name of known as hard-silver. This material still has a chemical corrosion resistance close to that of fine silver. In comparison to pure silver and fine-grain silver , AgCu3 exhibits increased mechanical strength as well as higher arc erosion resistance and mechanical wear resistance ''(Table 2.14)''.

Increasing the Cu content further also increases the mechanical strength of AgCu alloys and improves arc erosion resistance and resistance against material transfer while at the same time however simultaneously the tendency to oxide formation becomes detrimental. This causes - during switching under arcing conditions - an increase in contact resistance with rising numbers of operation. In special applications , where highest mechanical strength is recommended and a reduced chemical resistance can be tolerated, the eutectic AgCu alloy with 28 wt% of copper ''is used (<xr id="fig:Phase diagram of silver copper"/>)<!--(Fig. 2.52)'' is used-->. AgCu10 , also known as coin silver , has been replaced in many applications by composite silver-based materials while sterling silver (AgCu7.5) has never extended its important usage from decorative table wear and jewelry to industrial applications in electrical contacts.

Besides these binary alloys, ternary AgCuNi alloys are used in electrical contact applications. From this group , the material ARGODUR 27, an alloy of 98 wt% Ag with a 2 wt% Cu and nickel addition has found practical importance close to that of AgCu3. This material is characterized by high resistance to oxidation and low tendency to re-crystallization during exposure to high temperatures. Besides high mechanical stability this AgCuNi alloy also exhibits a strong resistance against arc erosion. Because of its high resistance against material transfer , the alloy AgCu24.5Ni0.5 has been used in the automotive industry for an extended time in the North American market. Caused by miniaturization and the related reduction in available contact forces in relays and switches , this material has been replaced widely because of its tendency to oxide formation.

Hard-silver alloys are widely used for switching applications in the information and energy technology for currents up to 10 A, in special cases also for higher current ranges ''(<xr id="tab:Application Examples and Forms of Supply for Silver and Silver Alloys"/>)<!--(Table 2.16)''-->. Dispersion hardened alloys of silver with 0.5 wt% MgO and NiO (ARGODUR 32) are produced by internal oxidation. While the melt-metallurgical alloy is easy to cold-work and form, the material becomes very hard and brittle after dispersion hardening. Compared to fine silver and hard-silver, this material has a greatly improved temperature stability and can be exposed to brazing temperatures up to 800°C without decreasing its hardness and tensile strength.Because of these mechanical properties and its high electrical conductivity ARGODUR 32 is mainly used in the form of contact springs that are exposed to high thermal and mechanical stresses in relays and contactors for aeronautic applications.

Dispersion hardened alloys of silver with 0.5 wt% MgO and NiO (ARGODUR 32) are produced by internal oxidation. While the melt<div class="multiple-metallurgical alloy is easy to cold-work and form the material becomes very hard and brittle after dispersion hardening. Compared to fine silver and hard-silver this material has a greatly improved temperature stability and can be exposed to brazing temperatures up to 800°C without decreasing its hardness and tensile strength.Because of these mechanical properties and its high electrical conductivityimages">

Table 2<figure id="fig:Phase diagram of silver copper"> [[File:Phase diagram of silver copper.13: Physical Properties jpg|left|thumb|<caption>Phase diagram of Silver and Silver Alloyssilver-copper</caption>]]</figure>

ARGODUR 32 is mainly used in the form <figure id="fig:Strain hardening of contact springs that are exposed toAgCu3 by cold working"> high thermal and mechanical stresses in relays, and contactors for aeronautic[[File:Strain hardening of AgCu3 by cold working.jpg|left|thumb|<caption>Strain hardening of AgCu3 by cold working</caption>]]applications.</figure>

Fig. 2.50<figure id="fig: Fine grain microstructureStrain hardening of AgCu5 by cold working"> [[File:Strain hardening of AgNi0AgCu5 by cold working.15 after 80% jpg|left|thumb|<caption>Strain hardening of AgCu5 by cold working</caption>]]and 1 hr annealing at 600°C</figure>

Fig. 2.51<figure id="fig:Softening of AgCu5 after annealing"> Phase diagram[[File:Softening of AgCu5 after annealing.jpg|left|thumb|<caption>Softening of AgCu5 after annealing for 1 hr after 80% cold working</caption>]]of silver-nickel</figure>

Fig. 2.52<figure id="fig:Strain hardening of AgCu 10 by cold working"> Phase diagram[[File:Strain hardening of AgCu 10 by cold working.jpg|left|thumb|<caption>Strain hardening of AgCu 10 by cold working</caption>]]of silver-copper</figure>

Fig. 2.53<figure id="fig:Softening of AgCu10 after annealing"> Phase diagram [[File:Softening of AgCu10 after annealing.jpg|left|thumb|<caption>Softening ofAgCu10 after annealing for 1 hr after 80% cold working</caption>]]silver-cadmium</figure>

Table 2<figure id="fig:Strain hardening of AgCu28 by cold working"> [[File:Strain hardening of AgCu28 by cold working.14: Mechanical Properties jpg|left|thumb|<caption>Strain hardening of Silver and Silver AlloysAgCu28 by cold working</caption>]]</figure>

Fig. 2.54<figure id="fig:Softening of AgCu28 after annealing"> Strain hardening[[File:Softening of AgCu28 after annealing.jpg|left|thumb|<caption>Softening of AgCu3by AgCu28 after annealing for 1 hr after 80% cold working</caption>]]</figure>

Fig<figure id="fig:Strain hardening of AgNi0. 215 by cold working"> [[File:Strain hardening of AgNiO15 by cold working.55:Softening jpg|left|thumb|<caption>Strain hardening of AgCu3after annealing for 1 hrafter 80% AgNiO15 by cold working</caption>]]</figure>

Fig<figure id="fig:Softening of AgNi0. 215 after annealing"> [[File:Softening of AgNiO15 after annealing.56:Strain hardening jpg|left|thumb|<caption>Softening of AgCu5 by coldAgNiO15 after annealing</caption>]]working</figure>

Fig. 2.57<figure id="fig:Strain hardening of ARGODUR 27"> Softening [[File:Strain hardening of AgCu5 afterannealing for 1 hr after 80% ARGODUR 27.jpg|left|thumb|<caption>Strain hardening of AgCu1.8Ni0.2 (ARGODUR 27) by coldworking</caption>]]working</figure>

Fig. 2.58<figure id="fig:Softening of ARGODUR 27 after annealing"> Strain hardening [[File:Softening of ARGODUR 27 after annealing.jpg|left|thumb|<caption>Softening of AgCu 10by AgCu1.8Ni0.2 (ARGODUR 27) after annealing for 1 hr after 80% cold working</caption>]]</figure></div><div class="clear"></div>

Fig. <figtable id="tab:Contact and Switching Properties of Silver and Silver Alloys"><caption>'''<!--Table 2.6115:Softening -->Contact and Switching Properties of AgCu28after annealing for 1 hr after80% cold workingSilver and Silver Alloys'''</caption>

Fig. {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !colspan="2.62:" | Properties|-Strain hardening of |Ag<br />AgNi0.15by cold working|Highest electrical and thermal conductivity, high affinity to sulfur (sulfide formation), low welding resistance, low contact resistance, very good formability |Oxidation resistant at higher make currents, limited arc erosion resistance, tendency to material transfer in DC circuits, easy to braze and weld to carrier materials|-|Ag Alloys |Increasing contact resistance with increasingCu content, compared to fine Ag higher arc erosion resistance and mechanical strength, lower tendency to material transfer|Good formability, good brazing and welding properties |}</figtable>

Fig. <figtable id="tab:Application Examples and Forms of Supply for Silver and Silver Alloys"><caption>'''<!--Table 2.6416:Strain hardening -->Application Examples and Forms ofARGODUR 27by cold workingSupply for Silver and Silver Alloys'''</caption>

Fig. 2.65{| class="twocolortable" style="text-align: left; font-size:12px"Softening|-!Material !Application Examples!Form of Supply|-|Ag<br />AgNi0.15<br />AgCu3<br />AgNi98NiCu2<br />ARGODUR 27 after annealing<br />AgCu24,5Ni0,5|Relays,<br />Micro switches,<br />Auxiliary current switches,<br />Control circuit devices,<br />Appliance switches,<br />Wiring devices (&le; 20A),<br />Main switches |'''Semi-finished Materials:''' <br />Strips, wires, contact profiles, clad contact strips, toplay profiles, seam- welded strips<br />'''Contact Parts:'''<br />Contact tips, solid and composite rivets, weld buttons; clad, welded and riveted contact parts|-|AgCu5<br />AgCu10<br />AgCu28 |Special applications|'''Semi-finished Materials:'''<br />Strips, wires, contact profiles, clad contact strips, seam-welded strips<br />'''Contact parts:'''<br />Contact tips, solid contact rivets, weld buttons; clad, welded and riveted contact parts|-|Ag99.5NiOMgO<br />ARGODUR 32|Miniature relays, aerospace relays and contactors, erosion wire for 1 hr after 80% cold workinginjection nozzles|Contact springs, contact carrier parts |}</figtable>

Table ====Silver-Palladium Alloys====The addition of 30 wt% Pd increases the mechanical properties as well as the resistance of silver against the influence of sulfur and sulfur containing compounds significantly (<xr id="tab:Physical Properties of Silver-Palladium Alloys"/><!--(Tab 2.1517)--> and <xr id="tab: Contact and Switching Mechanical Properties of Silver and Silver -Palladium Alloys"/>)<!--(Tab.2.18)-->. Alloyswith 40-60 wt% Pd have an even higher resistance against silver sulfide formation. At these percentage ranges however, the catalytic properties of palladium can influence the contact resistance behavior negatively. The formability also decreases with increasing Pd contents.

Table 2.16AgPd alloys are hard, arc erosion resistant, and have a lower tendency towards material transfer under DC loads (<xr id="tab: Application Examples Contact and Forms Switching Properties of Supply for Silver and Silver -Palladium Alloys"/>)<!--(Table 2.19)-->. On the other hand, the electrical conductivity is decreased at higher Pd contents. The ternary alloy AgPd30Cu5 has an even higher hardness, which makes it suitable for use in sliding contact systems.

AgPd alloys are mostly used in relays for the switching of medium to higher loads (> 60V, > 2A) as shown in <xr id===="tab:Application Examples and Forms of Suppl for Silver-Palladium Alloys====The addition "/><!--(Table 2.20)-->. Because of 30 wt% Pd increases the mechanical properties as well high palladium price, these formerly solid contacts have been widely replaced by multi-layer designs such as AgNi0.15 or AgNi10 with a thin Au surface layer. A broader field of application for AgPd alloys remains in thewear resistant sliding contact systems.resistance  <div class="multiple-images"><figure id="fig:Phase diagram of silver against the influence palladium">[[File:Phase diagram of silver palladium.jpg|left|thumb|<caption>Phase diagram of silver-palladium</caption>]]</figure> <figure id="fig:Strain hardening of sulfur and sulfur containingAgPd30 by cold working">compounds significantly ''(Tables 2[[File:Strain hardening of AgPd30 by cold working.17 and 2jpg|left|thumb|<caption>Strain hardening of AgPd30 by cold working</caption>]]</figure> <figure id="fig:Strain hardening of AgPd50 by cold working">[[File:Strain hardening of AgPd50 by cold working.18)''jpg|left|thumb|<caption>Strain hardening of AgPd50 by cold working</caption>]]</figure> <figure id="fig:Strain hardening of AgPd30Cu5 by cold working">[[File:Strain hardening of AgPd30Cu5 by cold working.jpg|left|thumb|<caption>Strain hardening of AgPd30Cu5 by cold working</caption>]]</figure> Alloys with 40-60 wt% Pd have an even higher resistance against silver sulfide<figure id="fig:Softening of AgPd30 AgPd50 AgPd30Cu5">formation[[File:Softening of AgPd30 AgPd50 AgPd30Cu5. At these percentage ranges however the catalytic properties jpg|left|thumb|<caption>Softening of AgPd30, AgPd50, and AgPd30Cu5 after annealing of1 hr after 80% cold working</caption>]]palladium can influence the contact resistance behavior negatively. The</figure></div>formability also decreases with increasing Pd contents.<div class="clear"></div>

AgPd alloys are mostly used in relays for the switching <figtable id="tab:Physical Properties of medium to higher loads(Silver-Palladium Alloys">60V, >2A) as shown in Table 2.20. Because of the high palladium price theseformerly solid contacts have been widely replaced by multi-layer designs suchas AgNi0.15 or AgNi10 with a thin Au surface layer. A broader field of applicationfor AgPd alloys remains in the wear resistant sliding contact systems.

Fig. <caption>'''<!--Table 2.6617: Phase diagram --> Physical Properties of silverSilver-palladiumPalladium Alloys'''</caption>

Fig{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Palladium Content<br />[wt%]!Density<br />[g/cm³]!Melting Point<br />or Range<br />[°C]!Electrical<br />Resistivity<br />[μΩ·cm]!Electrical<br />Conductivity<br />[MS/m]!Thermal<br />Conductivity<br />[W/m·K]!Temp. Coefficient of<br />the Electr. Resistance<br />[10^-3/K]|-|AgPd30|30|10.9|1155 - 1220|14.7|6.8|60|0.4|-|AgPd40|40|11.1|1225 - 1285|20.8|4.8|46|0.36|-|AgPd50|50|11. 2|1290 - 1340|32.67:3|3.1|34|0.23|-|AgPd60|60|11.4|1330 - 1385|41.7|2.4|29|0.12|-|AgPd30Cu5|30|10.8|1120 - 1165|15.6|6.4|28|0.37Strain hardening|}of AgPd30 by cold working</figtable>

Fig. <figtable id="tab:Mechanical Properties of Silver-Palladium Alloys"><caption>'''<!--Table 2.6918:-->Mechanical Properties of Silver-Palladium Alloys'''</caption>Strain hardening<table class="twocolortable">of <tr><th><p class="s12">Material</p></th><th><p class="s12">Hardness</p><p class="s12">Condition</p></th><th><p class="s12">Tensile Strength</p><p class="s12">R<span class="s31">_m</span>[MPa]</p></th><th><p class="s12">Elongation A</p><p class="s12">[%]min.</p></th><th><p class="s12">Vickers Hardness</p><p class="s12">HV</p></th></tr><tr><td><p class="s12">AgPd30</p></td><td><p class="s12">R 320</p><p class="s12">R 570</p></td><td><p class="s12">320</p><p class="s12">570</p></td><td><p class="s12">38</p><p class="s12">3</p></td><td><p class="s12">65</p><p class="s12">145</p></td></tr><tr><td><p class="s12">AgPd40</p></td><td><p class="s12">R 350</p><p class="s12">R 630</p></td><td><p class="s12">350</p><p class="s12">630</p></td><td><p class="s12">38</p><p class="s12">2</p></td><td><p class="s12">72</p><p class="s12">165</p></td></tr><tr><td><p class="s12">AgPd50</p></td><td><p class="s12">R 340</p><p class="s12">R 630</p></td><td><p class="s12">340</p><p class="s12">630</p></td><td><p class="s12">35</p><p class="s12">2</p></td><td><p class="s12">78</p><p class="s12">185</p></td></tr><tr><td><p class="s12">AgPd60</p></td><td><p class="s12">R 430</p><p class="s12">R 700</p></td><td><p class="s12">430</p><p class="s12">700</p></td><td><p class="s12">30</p><p class="s12">2</p></td><td><p class="s12">85</p><p class="s12">195</p></td></tr><tr><td><p class="s12">AgPd30Cu5</p></td><td><p class="s12">R 410</p><p class="s12">R 620</p></td><td><p class="s12">410</p><p class="s12">620</p></td><td><p class="s12">40</p><p class="s12">2</p></td><td><p class="s12">90</p><p class="s12">190</p></td></tr></table>by cold working</figtable>

<figtable id="tab:Contact and Switching Properties of Silver-Palladium Alloys"><caption>'''<!--Table 2.1719: Physical -->Contact and Switching Properties of Silver-Palladium Alloys''</caption>'

Table {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !colspan="2.18: Mechanical " | Properties of Silver|-|AgPd30-60|Corrosion resistant, tendency to Brown Powder formation increases with Pd content, low tendency to material transfer in DC circuits, high ductility |Resistant against Ag₂S formation, low contact resistance, increasing hardness with higher Pd content, AgPd30 has highest arc erosion resistance, easy to weld and clad|-Palladium Alloys|AgPd30Cu5 |High mechanical wear resistance|High Hardness |}</figtable>

<figtable id="tab:Application Examples and Forms of Suppl for Silver-Palladium Alloys"><caption>'''<!--Table 2.20: -->Application Examples and Forms of Suppl for Silver-Palladium Alloys'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></th><th><p class="s12">Application Examples</p></th><th><p class="s12">Form of Supply</p></th></tr><tr><td><p class="s12">AgPd 30-60</p></td><td><p class="s12">Switches, relays, push-buttons,</p><p class="s12">connectors, sliding contacts</p></td><td><p class="s12">'''Semi-finished Materials:'''</p><p class="s12">Wires, micro profiles (weld tapes), clad</p><p class="s12">contact strips, seam-welded strips</p><p class="s12">'''Contact Parts:'''</p><p class="s12">Solid and composite rivets, weld buttons;</p><p class="s12">clad and welded contact parts, stamped parts</p></td></tr><tr><td><p class="s12">AgPd30Cu5</p></td><td><p class="s12">Sliding contacts, slider tracks</p></td><td><p class="s12">Wire-formed parts, contact springs, solid</p><p class="s12">and clad stamped parts</p></td></tr></table></figtable>

====Silver-Nickel (SINIDUR) Materials====Since silver and nickel are not soluble in each other in solid form and also show very limited solubility in the liquidphase have only very limited solubility , silver nickel composite materials withhigher Ni contents can only be produced by powder metallurgy. During extrusionof sintered Ag/Ni billets into wires, strips and rods , the Ni particles embedded inthe Ag matrix are stretched and oriented in the microstructure into a pronouncedfiber structure ''(Figs<xr id="fig:Micro structure of AgNi9010"/><!--(Fig. 2.75)--> and <xr id="fig:Micro structure of AgNi 8020"/>)<!--(Fig. 2.76)--> The high density produced during hot extrusion, aids the arc erosion resistance of these materials (<xr id="tab:Physical Properties of Silver-Nickel (SINIDUR) Materials"/>)<!--(Tab 2.21)-->. The typical application of Ag/Ni contact materials is in devices for switching currents of up to 100A (<xr id="tab:Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"/>)<!--(Table 2.24)-->. In this range, they are significantly more erosion resistant than silver or silver alloys. In addition, they exhibit with nickel contents < 20 wt% a low and over their operational lifetime consistent contact resistance and good arc moving properties. In DC applications Ag/Ni materials exhibit a relatively low tendency of material transfer distributed evenly over the contact surfaces (<xr id="tab:Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials"/>)<!--(Table 2.23)-->. Typically Ag/Ni materials are usually produced with contents of 10-40 wt% Ni. The most common used materials Ag/Ni 10 and Ag/Ni 20- and also Ag/Ni 15, mostly used in north america-, are easily formable and applied by cladding (<xr id="fig:Strain hardening of AgNi9010 by cold working"/>,<!--(Fig. 2.71)--> <xr id="fig:Softening of AgNi9010 after annealing"/>,<!--(Fig. 2.72)--> <xr id="fig:Strain hardening of AgNi8020"/>, <!--(Fig. 2.7673)--> <xr id="fig:Softening of AgNi8020 after annealing"/>)<!--(Fig. 2.74)-->. They can be, without any additional welding aids, economically welded and brazed to the commonly used contact carrier materials.The Ag/Ni materials with nickel contents of 30 and 40 wt% are used in switching devices, requiring a higher arc erosion resistance and where increases in contact resistance can be compensated through higher contact forces. The most important applications for Ag/Ni contact materials are typically in relays, wiring devices, appliance switches, thermostatic controls, auxiliary switches and small contactors with nominal currents > 20A (<xr id="tab:Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"/>)<!--(Table 2.24)''-->.

The high density produced during hot extrusion aids the arc erosion resistance<figtable id="tab:Physical Properties of Silver-Nickel (SINIDUR) Materials">of these materials <caption>'''(Tables <!--Table 2.21 and 2.22):-->Physical Properties of Silver-Nickel Materials'''. The typical application of Ag</Nicaption><table class="twocolortable">contact materials is in devices for switching currents of up to 100A ''<tr><th>Material</th><th>Silver Content</th><th>Density</th><th>Melting Point</th><th>ElectricalResistivity<i>p</i></th><th colspan="2">Electrical Resistivity (Table 2.24soft)''.</th></tr>In this range they are significantly more erosion resistant than silver or silver<tr>alloys. In addition they exhibit with nickel contents <20 th></th><th>[wt% a low and over their]</th><th>[g/cm³]</th><th>[°C]</th><th>[µΩ·cm]</th>operational lifetime consistent contact resistance and good arc moving<th>[% IACS]</th><th>[MS/m]</th></tr>properties<tr><td><p class="s11">Ag/Ni 90/10</p><p class="s11"></p></td><td><p class="s11">89 - 91</p></td><td><p class="s11">10.2 - 10.3</p></td><td><p class="s11">960</p></td><td><p class="s11">1.82 - 1.92</p></td><td><p class="s12">90 - 95</p></td><td><p class="s12">52 - 55</p></td></tr><tr><td><p class="s11">Ag/Ni 85/15</p><p class="s11"></p></td><td><p class="s11">84 - 86</p></td><td><p class="s11">10.1 - 10.2</p></td><td><p class="s11">960</p></td><td><p class="s11">1.89 - 2.0</p></td><td><p class="s12">86 - 91</p></td><td><p class="s12">50 - 53</p></td></tr><tr><td><p class="s11">Ag/Ni 80/20</p><p class="s11"></p></td><td><p class="s11">79 - 81</p></td><td><p class="s11">10.0 - 10. In DC applications 1</p></td><td><p class="s11">960</p></td><td><p class="s11">1.92 - 2.08</p></td><td><p class="s12">83 - 90</p></td><td><p class="s12">48 - 52</p></td></tr><tr><td><p class="s11">Ag/Ni materials exhibit a relatively low tendencyof material transfer distributed evenly over the contact surfaces ''(Table 70/30</p><p class="s11"></p></td><td><p class="s11">69 - 71</p></td><td><p class="s11">9.8</p></td><td><p class="s11">960</p></td><td><p class="s11">2.23)''44</p></td><td><p class="s12">71</p></td><td><p class="s12">41</p></td></tr><tr><td><p class="s11">Ag/Ni 60/40</p><p class="s11"></p></td><td><p class="s11">59 - 61</p></td><td><p class="s11">9.7</p></td><td><p class="s11">960</p></td><td><p class="s11">2.70</p></td><td><p class="s12">64</p></td><td><p class="s12">37</p></td></tr></table></figtable>

The most important applications for Ag/Ni contact materials are typically in<figtable id="tab:tab2.22">relays, wiring devices, appliance switches, thermostatic controls, auxiliaryswitches, and small contactors with nominal currents <caption>20A ''('<!-- Table 2.24)22:-->Mechanical Properties of Silver-Nickel Materials''.'</caption>

Table 2.21{| class="twocolortable" style="text-align: left; font-size: Physical Properties of Silver12px"|-Nickel !Material !Hardness Condition!Tensile Strength R_m [Mpa]!Elongation A (SINIDURsoft annealed) Materials[%] min.!Vickers Hardness HV 10|-|Ag/Ni 90/10<br />|soft<br />R 220<br />R 280<br />R 340<br />R 400|< 250<br />220 - 280<br />280 - 340<br />340 - 400<br />> 400|25<br />20<br />3<br />2<br />1|< 50<br />50 - 70<br />65 - 90<br />85 - 105<br />> 100|-|Ag/Ni 85/15<br />|soft<br />R 300<br />R 350<br />R 380<br />R 400|< 275<br />250 - 300<br />300 - 350<br />350 - 400<br />> 400|20<br />4<br />2<br />2<br />1|< 70<br />70 - 90<br />85 - 105<br />100 - 120<br />> 115|-|Ag/Ni 80/20<br />|soft<br />R 300<br />R 350<br />R 400<br />R 450|< 300<br />300 - 350<br />350 - 400<br />400 - 450<br />> 450|20<br />4<br />2<br />2<br />1|< 80<br />80 - 95<br />90 - 110<br />100 - 125<br />> 120|-|Ag/Ni 70/30<br />|R 330<br />R 420<br />R 470<br />R 530|330 - 420<br />420 - 470<br />470 - 530<br />> 530|8<br />2<br />1<br />1|80<br />100<br />115<br />135|-|Ag/Ni 60/40<br />|R 370<br />R 440<br />R 500<br />R 580|370 - 440<br />440 - 500<br />500 - 580<br />> 580|6<br />2<br />1<br />1|90<br />110<br />130<br />150|}</figtable>

Fig. 2.71<div class="multiple-images"><figure id="fig:Strain hardening of AgNi9010 by cold working">[[File:Strain hardening of AgNi9010 by cold working.jpg|right|thumb|<caption>Strain hardeningof Ag/Ni 90/10 by cold working</caption>]]</figure>

Fig. 2.72<figure id="fig:Softening of AgNi9010 after annealing">[[File:Softening of AgNi9010 after annealing.jpg|right|thumb|<caption>Softening of Ag/Ni 90/10after annealingfor 1 hr after 80% cold working</caption>]]</figure>

Fig. 2.73<figure id="fig:Strain hardening of AgNi8020">[[File:Strain hardening of AgNi8020.jpg|right|thumb|<caption>Strain hardeningof Ag/Ni 80/20 by cold working</caption>]]</figure>

Fig. 2.74<figure id="fig:Softening of AgNi8020 after annealing">[[File:Softening of AgNi8020 after annealing.jpg|right|thumb|<caption>Softening of Ag/Ni 80/20after annealingfor 1 hr after 80% cold working</caption>]]</figure>

Fig. 2<figure id="fig:Micro structure of AgNi9010">[[File:Micro structure of AgNi9010.75: jpg|right|thumb|<caption>Micro structure of Ag/Ni 90/10 a) perpendicular to the extrusion directionb) parallel to the extrusion direction</caption>]]</figure>

Fig. 2<figure id="fig:Micro structure of AgNi 8020">[[File:Micro structure of AgNi 8020.76: jpg|right|thumb|<caption>Micro structure of Ag/Ni 80/20 a) perpendicular to the extrusion directionb) parallel t o to the extrusion direction</caption>]]</figure></div><div class="clear"></div>

<figtable id="tab:Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials"><caption>'''<!-- Table 2.2423:-->Contact and Switching Properties of Silver-Nickel Materials'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Properties|-|Ag/Ni <br />|High arc erosion resistance at switching currents up to 100A,<br />Resistance against welding for starting current up to 100A,<br />low and over the electrical contact life nearly constant contact resistance for Ag/Ni 90/10 and Ag/Ni 80/20,<br />ow and spread-out material transfer under DC load,<br />non-conductive erosion residue on isolating components resulting in only minor change of the dielectric strength of switching devices,<br />good arc moving properties,<br />good arc extinguishing properties,<br />good or sufficient ductility depending on the Ni content,<br />easy to weld and braze|}</figtable>  <figtable id="tab: Application Examples and Forms of Supplyfor Silver-Nickel (SINIDUR) Materials"><caption>'''<!--Table 2.24:-->Application Examples and Forms of Supply for Silver-Nickel Materials'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Application Examples!Switching or Nominal Current!Form of Supply|-|Ag/Ni 90/10-80/20|Relays<br /> Automotive Relays - Resistive load - Motor load|> 10A<br />> 10A|rowspan="9" | '''Semi-finisched Materials:'''<br />Wires, profiles,<br />clad strips,<br />Seam-welded strips,<br />Toplay strips <br />'''Contact Parts:'''<br />Contact tips, solid<br />and composite<br />rivets, Weld buttons,<br />clad, welded,<br />brazed, and riveted<br />contact parts|-|Ag/Ni 90/10, Ag/Ni 85/15-80/20|Auxiliary current switches|&le; 100A|-|Ag/Ni 90/10-80/20|Appliance switches|&le; 50A|-|Ag/Ni 90/10|Wiring devices|&le; 20A|-|Ag/Ni 90/10|Main switches, Automatic staircase illumination switches|&le; 100A|-|Ag/Ni 90/10-80/20|Control<br />Thermostats|> 10A<br />&le; 50A|-|Ag/Ni 90/10-80/20|Load switches|&le; 20A|-|Ag/Ni 90/10-80/20|Contactors circuit breakers|&le; 100A|-|Ag/Ni 90/10-80/20<br />paired with Ag/C 97/3-96/4|Motor protective circuit breakers|&le; 40A|-|Ag/Ni 80/20-60/40<br />paired with Ag/C 96/4-95/5|Fault current circuit breakers|&le; 100A|rowspan="2" | Rods, Profiles,<br />Contact tips, Formed parts,<br />brazed and welded<br />contact parts|-|Ag/Ni 80/20-60/40<br />paired with Ag/C 96/4-95/5|Power switches|> 100A|}</figtable>

The family of silver-metal oxide contact materials includes the material groups:silver-cadmium oxide (DODURIT CdO), silver-tin oxide (SISTADOX), and silverzincoxide (DODURIT ZnO). Because of their very good contact and switchingproperties like high resistance against welding, low contact resistance, and higharc erosion resistance, silver-metal oxides have gained an outstanding positionin a broad field of applications. They are mainly are used in low voltage electricalswitching devices like relays, installation and distribution switches, appliances,industrial controls, motor controls, and protective devices ''(<xr id="tab:Application Examples of Silver–Metal Oxide Materials"/>)<!--(Table 2.1331)''-->.

*'''Silver-cadmium oxide (DODURIT CdO) materials'''

Silver-cadmium oxide (DODURIT CdO) materials with 10-15 wt% are producedby both, internal oxidation and powder metallurgical methods ''(Table 2.25)''.

The manufacturing of strips and wires by internal oxidation starts with a moltenalloy of silver and cadmium. During a heat treatment below it's melting point in aan oxygen rich atmosphere in of such a homogeneous alloy , the oxygen diffuses fromthe surface into the bulk of the material and oxidizes the Cd to CdO in a more orless fine particle precipitation inside the Ag matrix. The CdO particles are ratherfine in the surface area and are becoming getting larger further away towards the centerof the material ''(<xr id="fig:Micro structure of AgCdO9010"/>)<!--(Fig. 2.83)''-->.

During the manufacturing of Ag/CdO contact material by internal oxidation , theprocesses vary depending on the type of semi-finished material.For Ag/CdO wires , a complete oxidation of the AgCd wire is performed, followedby wire-drawing to the required diameter ''(<xr id="fig:Strain hardening of internally oxidized AgCdO9010"/><!--(Figs. 2.77 )--> and <xr id="fig:Softening of internally oxidized AgCdO9010"/>)<!--(Fig. 2.78)''-->. The resultingmaterial is used for example , in the production of contact rivets. For Ag/CdO stripmaterials two processes are commonly used: Cladding of an AgCd alloy stripwith fine silver , followed by complete oxidation , results in a strip material with asmall depletion area in the center of it's thickness and a an Ag backing suitable foreasy attachment by brazing (sometimes called “Conventional "Conventional Ag/CdO”CdO"). Usinga technology that allows the partial oxidation of a dual-strip AgCd alloy materialin a higher pressure pure oxygen atmosphere , yields a composite Ag/CdO stripmaterial that has - besides a relatively fine CdO precipitation - also a an easily brazableAgCd alloy backing ''(Fig. 2.85)''. These materials (DODURIT CdO ZH) are mainlyused as the basis for contact profiles and contact tips.

During powder metallurgical production , the powder mixed made by differentprocesses are typically converted by pressing, sintering and extrusion to wiresand strips. The high degree of deformation during hot extrusion , produces auniform and fine dispersion of CdO particles in the Ag matrix while at the sametime achieving a high density which is advantageous for good contact properties''(<xr id="fig:Micro structure of AgCdO9010P"/>)<!--(Fig. 2.84)''-->. To obtain a backing suitable for brazing, a fine silver layer is appliedby either com-pound extrusion or hot cladding prior to or right after the extrusion''(Fig. 2.86)''.

For larger contact tips, and especially those with a rounded shape, the single tipPress-Sinter-Repress process (PSR) offers economical advantages. Thepowder mix is pressed in into a die close to the final desired shape, the “green” "green" tipsare sintered, and in most cases , the repress process forms the exact final exact shapewhile at the same time , increasing the contact density and hardness.

Using different silver powders and minor additives for the basic Ag and CdO, starting materials can help influence certain contact properties for specializedapplications.

Fig. 2.77<div class="multiple-images"><figure id="fig:Strain hardening of internally oxidized AgCdO9010">[[File:Strain hardening of internally oxidized AgCdO9010.jpg|left|thumb|<caption>Strain hardening of internally oxidizedAg/CdO 90/10 by cold working</caption>]]</figure>

Fig. 2.78<figure id="fig:Softening of internally oxidized AgCdO9010">[[File:Softening of internally oxidizedAgCdO9010.jpg|left|thumb|<caption>Softening of internally oxidized (i.o.) Ag/CdO 90/10 after annealingfor 1 hr after 40% cold working</caption>]]</figure>

Table 2.25<figure id="fig: Physical and Mechanical Properties as well as Manufacturing Processes andStrain hardening of AgCdO9010P">Forms [[File:Strain hardening of Supply AgCdO9010P.jpg|left|thumb|<caption>Strain hardening of Extruded Silver Cadmium Oxidepowder metallurgical (DODURIT p.m.) Ag/CdO) Contact Materials90/10 by cold working</caption>]]</figure>

Fig. 2.79<figure id="fig:Softening of AgCdO9010P after annealing">Strain hardening [[File:Softening of AgCdO9010P after annealing.jpg|left|thumb|<caption>Softening ofpowder metallurgical Ag/CdO 90/10 P by after annealing for 1 hr after 40% cold working</caption>]]</figure>

Fig. 2.80<figure id="fig: SofteningStrain hardening of AgCdO8812">[[File:Strain hardening of AgCdO8812.jpg|left|thumb|<caption>Strain hardening of powder metallurgical Ag/CdO 9088/12</10 P after annealingcaption>]]for 1 hr after 40% cold working</figure>

Fig. 2.81<figure id="fig:Softening of AgCdO8812WP after annealing">Strain hardening[[File:Softening of AgCdO8812WP after annealing.jpg|left|thumb|<caption>Softening of powder metallurgical Ag/CdO 88/12 WPafter annealing for 1 hr after different degrees of cold working</caption>]]</figure>

Fig. 2.82<figure id="fig:Micro structure of AgCdO9010">Softening [[File:Micro structure of AgCdO9010.jpg|left|thumb|<caption>Micro structure of Ag/CdO 8890/10 i.o. a) close to surface b) in center area</12WP after annealingcaption>]]for 1 hr after different degrees ofcold working</figure>

Fig<figure id="fig:Micro structure of AgCdO9010P">[[File:Micro structure of AgCdO9010P. 2.83: jpg|left|thumb|<caption>Micro structure of Ag/CdO 90/10 ip.om. : a) close perpendicular to surfaceextrusion direction b) in center areaparallel to extrusion direction</caption>]]</figure>

Fig. 2.84: Micro structure of Ag</CdO 90div><div class="clear"></10 P:a) perpendicular to extrusion directionb) parallel to extrusion directiondiv>

Fig*'''Silver–tin oxide materials'''Over the past years, many Ag/CdO contact materials have been replaced by Ag/SnO₂ based materials with 2-14 wt% SnO₂ because of the toxicity of Cadmium. This changeover was further favored by the fact that Ag/SnO₂ contacts quite often show improved contact and switching properties such as lower arc erosion, higher weld resistance and a significant lower tendency towards material transfer in DC switching circuits (<xr id="tab:Contact and Switching Properties of Silver–Metal Oxide Materials"/>)<!--(Table 2.30)-->.86Ag/SnO₂ materials have been optimized for a broad range of applications by other metal oxide additives and modification in the manufacturing processes that result in different metallurgical, physical and electrical properties (<xr id="tab: Micro structure of AgCdO 88tab2.28"/12 WP><!--(Tab. 2.28)--> and <xr id="tab: atab2.29"/>) perpendicular to extrusion directionb<!--(Table 2.29) parallel to extrusion direction-->.

*Silver–tin oxide(SISTADOX)materialsOver the past years, many Ag/CdO contact materials have been replaced byManufacturing of Ag/SnO₂ based materials with 2-14 by ''internal oxidation'' is possible in principle, but during heat treatment of alloys containing > 5 wt% SnO₂ because of tin in oxygen, dense oxide layers formed on the surface of the material prohibit the further diffusion of oxygen into the toxicity bulk ofCadmiumthe material. This changeover was further favored by By adding Indium or Bismuth to the alloy, the fact internal oxidation is possible and results in materials that Ag/SnO₂contacts quite often typically are rather hard and brittle and may show improved somewhat elevated contact resistance and switching properties is limited to applications in relays. Adding a brazable fine silver layer to such materials results in a semifinished material, suitable for the manufacture aslower arc erosion, higher smaller weld resistance, and a significant lower tendencytowards material transfer in DC switching circuits ''profiles (Table 2.30)''. <xr id="fig:Micro structure of AgSnO2 92 8 WTOS F"/SnO>)<sub>!--(Fig. 2</sub.116)-->. Because of their resistance to material transfer and low arc erosion, these materials have been optimized find for example a broad range broader application in automotive relays (<xr id="tab:Application Examples of applications by other metaloxide additives and modification in the manufacturing processes that result indifferent metallurgical, physical and electrical properties ''Silver–Metal Oxide Materials"/>)<!--(Table 2.2931)''-->.

Manufacturing ''Powder metallurgy'' plays a significant role in the manufacturing of Ag/SnO₂ by ''internal oxidation'' is possible in principle, butduring heat treatment of alloys containing contact materials. Besides SnO₂ 5 a smaller amount (<1 wt% ) of tin in oxygenone or more other metal oxides such as WO₃, MoO₃, dense oxideCuO and/or Bi₂O₃ are added. Theselayers formed on additives improve the surface wettability of the material prohibit oxide particles and increase the further diffusion viscosity ofoxygen into the bulk of the materialAg melt. By adding Indium or Bismuth They also provide additional benefits to the alloy theinternal oxidation is possible mechanical and results in materials that typically are rather hardand brittle and may show somewhat elevated arcing contact resistance and is limitedto applications in relays. To make a ductile material with fine oxide dispersion(SISTADOX TOS F) ''(Fig. 2.114)'' it is necessary to use special process variationsin oxidation and extrusion which lead to materials with improved properties inrelays. Adding a brazable fine silver layer to such of materials results in a semifinishedmaterial suitable for the manufacture as smaller weld profilesthis group (SISTADOX WTOS F) ''(Fig<xr id="tab:tab2. 2.11626"/>)''. Because of their resistance to materialtransfer and low arc erosion these materials find for example a broaderapplication in automotive relays ''<!--(Table 2.3126)''-->.

''Powder metallurgy'' plays a significant role in the manufacturing of Ag/SnO₂contact materialsfigtable id="tab:tab2. Besides SnO_{2</sub26"> a smaller amount (<1 wt%) of one or moreother metal oxides such as WO<subcaption>3'''}, MoO<sub>3</sub!--Table 2.26:-->, CuO Physical and/or Bi₂O₃ are added. Theseadditives improve the wettability of the oxide particles Mechanical Properties as well as Manufacturing Processes and increase the viscosityForms of the Ag melt. They also provide additional benefits to the mechanical andarcing contact properties Supply of materials in this group 'Extruded Silver-Tin Oxide Contact Materials'(Table 2.26)''.</caption>

In the manufacture the initial powder mixes different processes are applied{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Additives!Theoretical<br />Density<br />[g/cm³]!Electrical<br />Conductivity<br />[MS/m]!Vickers<br />Hardness<br />[HV0,1]which provide specific advantages of the resulting materials in respect to their!Tensile<br />Strength<br />[MPa]contact properties ''!Elongation (Figssoft annealed)<br />A[%]min. !Manufacturing<br />Process!Form of Supply|-|Ag/SnO₂ 98/2 SPW|97 - 99|WO₃|10,4|59 ± 2|57 ± 15|215|35|Powder Metallurgy|1|-|Ag/SnO₂ 92/8 SPW|91 - 93|WO₃|10,1|51 ± 2|62 ± 15|255|25|Powder Metallurgy|1|-|Ag/SnO₂ 90/10 SPW|89 - 91|WO₃|10|47 ± 5||250|25|Powder Metallurgy|1|-|Ag/SnO₂ 88/12 SPW|87 - 89|WO₃|9.9|46 ± 5|67 ± 15|270|20|Powder Metallurgy|1|-|Ag/SnO₂ 92/8 SPW4|91 - 93|WO₃|10,1|51 ± 2|62 ± 15|255|25|Powder Metallurgy|1,2|-|Ag/SnO₂ 90/10 SPW4|89 - 91|WO₃|10|||||Powder Metallurgy|1,2|-|Ag/SnO₂ 88/12 SPW4<br />|87 – - 89|WO₃|9,8|46 ± 5|80 ± 10|||Powder Metallurgy|1,2|-|Ag/SnO₂ 88/12 SPW6|87 - 89|MoO₃|9.119)''8|42 ± 5|70 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 97/3 SPW7|96 - 98|Bi₂O₃ and WO₃||||||Powder Metallurgy|2|-|Ag/SnO₂ 90/10 SPW7|89 - 91|Bi₂O₃ and WO₃|9,9|||||Powder Metallurgy|2|-|Ag/SnO₂ 88/12 SPW7|87 - 89|Bi₂O₃ and WO₃|9. Some of them are described here as8|42 ± 5|70 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 98/2 PMT1|97 - 99|Bi₂O₃ and CuO|10,4|57 ± 2||215|35|Powder Metallurgy|1,2|-|Ag/SnO₂ 96/4 PMT1|95 - 97|Bi₂O₃ and CuO||||||Powder Metallurgy|1,2|-|Ag/SnO₂ 94/6 PMT1|93 - 95|Bi₂O₃ and CuO||||||Powder Metallurgy|1,2|-|Ag/SnO₂ 92/8 PMT1|91 - 93|Bi₂O₃ and CuO|10|50 ± 2|62 ± 15|240|25|Powder Metallurgy|1,2|-|Ag/SnO₂ 90/10 PMT1|89 - 91|Bi₂O₃ and CuO|10|48 ± 2|65 ± 15|240|25|Powder Metallurgy|1,2|-|Ag/SnO₂ 88/12 PMT1|87 - 89|Bi₂O₃ and CuO|9,9|46 ± 5||260|20|Powder Metallurgy|1,2|-|Ag/SnO₂ 90/10 PE|89 - 91|Bi₂O₃ and CuO|9,8|48 ± 2|55 - 100|230 - 330|28|Powder Metallurgy|1|-|Ag/SnO₂ 88/12 PE|87 - 89|Bi₂O₃ and CuO|9,7|46 ± 5|60 - 106|235 - 330|25|Powder Metallurgy|1|-|Ag/SnO₂ 88/12 PMT2|87 - 89|CuO|9,9||90 ± 10|||Powder Metallurgy|1,2|-|Ag/SnO₂ 86/14 PMT3|85 - 87|Bi₂O₃ and CuO|9,8||95 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 94/6 LC1|93 - 95|Bi₂O₃ and In₂O₃|9,8|45 ± 5|55 ± 10|follows:|:'''a) |Powder blending from single component powders''' Metallurgy|2|-|Ag/SnO₂ 90/10 POX1|89 - 91|In₂O₃|9,9|50 ± 5|85 ± 15|310|25|Internal Oxidation|1,2|-|Ag/SnO₂ 90/10 POX1|87 - 89|In₂O₃|9,8|48 ± 5|90 ± 15|325|25|Internal Oxidation|1,2|-|Ag/SnO<brsub>2</sub> 90/10 POX1|85 - 87 |In this common process all components including additives that are part of the powder mix are blended as single powders. The blending is usually performed in the dry stage in blenders of different design.₂O₃|9,6|45 ± 5|95 ± 15|330|20|Internal Oxidation|1,2|-|}</figtable>

:'''b) Powder blending on the basis of doped powders''' <br> For incorporation of additive oxides in the SnO_{1 = Wires, Rods, Contact rivets, 2} powder the reactive spray process (RSV) has shown advantages. This process starts with a waterbased solution of the tin and other metal compounds. This solution is nebulized under high pressure and temperature in a reactor chamber. Through the rapid evaporation of the water each small droplet is converted into a salt crystal and from there by oxidation into a tin oxide particle in which the additive metals are distributed evenly as oxides. The so created doped AgSnO2 powder is then mechanically mixed with silver powder.= Strips, Profiles, Contact tips

In the manufacture for the initial powder mixes, different processes are applied which provide specific advantages of the resulting materials in respect to their contact properties <!--[[#figures|(Figs. 43 – 75)]]-->. Some of them are described here as follows::'''a) Powder blending from single component powders''' <br> In this common process all components, including additives that are part of the powder mix, are blended as single powders. The blending is usually performed in the dry stage in blenders of different design. :'''db) Powder blending based on internally oxidized alloy the basis of doped powders''' <br> A combination For incorporation of additive oxides in the SnO₂ powder metallurgy and internal oxidation this , the reactive spray process has shown advantages. This process starts with atomized Ag alloy powder which a waterbased solution of the tin and other metal compounds. This solution is subsequently oxidized nebulized under high pressure and temperature in pure oxygena reactor chamber. During this process Through the rapid evaporation of the Sn water, each small droplet is converted into a salt crystal and other metal components are from there gets transformed to metal by oxidation into a tin oxide and precipitated inside particle in which the additive metals are distributed evenly as oxides. The so created doped AgSnO₂ powder is then mechanically mixed with silver matrix of each powder particle.

:'''ec) Powder blending based on chemically precipitated compound coated oxide powders''' <br> A silver salt solution In this process, tin oxide powder is added to a suspension of blended with lower melting additive oxides such as for example SnOAg₂ together with a precipitation agent. In a chemical reaction silver MoO₄ and silver oxide respectively are precipitated around the additive metal oxide particles who act as crystallization sitesthen heat treated. Further chemical treatment then reduces the silver oxide with the resulting precipitated powder being a mix of Ag and The SnO₂particles are coated in this step with a thin layer of the additive oxide.

Further processing of these differently produced :'''d) Powder blending based on internally oxidized alloy powders follows theconventional processes ''' <br> A combination of pressing, sintering powder metallurgy and hot extrusion to wires andstripsinternal oxidation this process starts with atomized Ag alloy powder which is subsequently oxidized in pure oxygen. From these contact parts such as contact rivets During this process the Sn and tips other metal components aremanufactured. To obtain a brazable backing transformed to metal oxide and precipitated inside the same processes as used forAg/CdO are applied. As for Ag/CdO, larger contact tips can also bemanufactured more economically using the press-sinter-repress (PSR) process''(Table 2.27)silver matrix of each powder particle.''

Fig:'''e) Powder blending based on chemically precipitated compound powders''' <br> A silver salt solution is added to a suspension of for example SnO₂ together with a precipitation agent. 2In a chemical reaction, silver and silver oxide respectively are precipitated around the additive metal oxide particles, who act as crystallization sites.87:Strain hardening Further chemical treatment then reduces the silver oxide with the resulting precipitated powder, being a mix ofAg/and SnO₂ 92/8 PE by cold working.

FigFurther processing of these differently produced powders follows the conventional processes of pressing, sintering and hot extrusion to wires and strips. From these contact parts, contact rivets and tips are manufactured. 2To obtain a brazable backing, the same processes as used for Ag/CdO are applied.88As for Ag/CdO, larger contact tips can also be manufactured using the press-sinter-repress (PSR) process (<xr id="tab:Softening Physical Properties ofAgPowder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process"/SnO>)<sub!--(Table 2.27)-->2.</subdiv id="figures"> 92/8 PE after annealingfor 1 hr after 40% cold working

Table 2.26<div class="multiple-images"><figure id="fig: Physical and Mechanical Properties as well as Manufacturing Processes andStrain hardening of AgSNO2 92 8 PE">Forms [[File:Strain hardening of Supply AgSNO2 92 8 PE.jpg|left|thumb|<caption>Strain hardening of Extruded Silver-Tin Oxide (SISTADOX) Contact MaterialsAg/SnO₂ 92/8 PE by cold working</caption>]]</figure>

Fig. 2.89<figure id="fig:Softening of AgSnO2 92 8 PE"> Strain hardening [[File:Softening of AgSnO2 92 8 PE.jpg|left|thumb|<caption>Softening ofAg/SnO₂ 8892/12 8 PE by after annealing for 1 hr after 40% cold working</caption>]]</figure>

Fig. 2.90<figure id="fig:Strain hardening of Ag SnO2 88 12 PE"> Softening [[File:Strain hardening of Ag SnO2 88 12 PE.jpg|left|thumb|<caption>Strain hardening of Ag/SnO₂ 88/12 PEafter annealing for1 hr after 40% by cold working</caption>]]</figure>

Fig. 2.91<figure id="fig:Softening of Ag SnO2 88 12 PE after annealing"> Strain hardening [[File:Softening of Ag SnO2 88 12 PE after annealing.jpg|left|thumb|<caption>Softening of oxidizedAg/SnO₂ 88/12 PW4 by PE after annealing for 1 hr after 40% cold working</caption>]]</figure>

Fig. 2.92<figure id="fig:Strain hardening of oxidized AgSnO2 88 12 PW4"> Softening [[File:Strain hardening of oxidized AgSnO2 88 12 PW4.jpg|left|thumb|<caption>Strain hardening of oxidized Ag/SnO₂ 88/12 PW4 afterannealing for 1 hrafter 30% by cold working</caption>]]</figure>

Fig. 2.93<figure id="fig:Softening of Ag SnO2 88 12 PW4 after annealing"> Strain hardening [[File:Softening of Ag SnO2 88 12 PW4 after annealing.jpg|left|thumb|<caption>Softening ofAg/SnO₂ 9888/2 PXby 12 PW4 after annealing for 1 hr after 30% cold working</caption>]]</figure>

Fig. 2.94<figure id="fig:Strain hardening of internally oxidized Ag SnO2 88 12 TOS F"> Softening [[File:Strain hardening of internally oxidized Ag SnO2 88 12 TOS F.jpg|left|thumb|<caption>Strain hardening ofinternally oxidized Ag/SnO₂ 9888/2 PXafter annealingfor 1 hr after 80%12 TOS F by cold working</caption>]]</figure>

Fig 2.95<figure id="fig:Softening of Ag SnO2 88 12 TOS F after annealing"> Strain hardening[[File:Softening of Ag SnO2 88 12 TOS F after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 9288/8 PXby 12 TOS F after annealing for 1 hr after 30% cold working</caption>]]</figure>

Fig. 2.96<figure id="fig:Strain hardening of internally oxidized Ag SnO2 88 12P"> Softening [[File:Strain hardening ofinternally oxidized Ag SnO2 88 12P.jpg|left|thumb|<caption>Strain hardening of internally oxidized Ag/SnO₂ 9288/8 PXafter annealing for 1 hrafter 40% 12P by cold working</caption>]]</figure>

Fig. 2.97<figure id="fig:Softening of Ag SnO2 88 12P after annealing"> Strain hardening [[File:Softening of Ag SnO2 88 12P after annealing.jpg|left|thumb|<caption>Softening of internallyoxidizedAg/SnO₂ 88/12 TOS Fby SP after annealing for 1 hr after 40% cold working</caption>]]</figure>

Fig. 2.98<figure id="fig:Strain hardening of Ag SnO2 88 12 WPD"> Softening [[File:Strain hardening of Ag SnO2 88 12 WPD.jpg|left|thumb|<caption>Strain hardening ofAg/SnO₂ 88/12 TOS F afterannealing for 1 hr after 30%WPD by cold working</caption>]]</figure>

Fig. 2.99<figure id="fig:Softening of Ag SnO2 88 12 WPD after annealing"> Strain hardening [[File:Softening of Ag SnO2 88 12 WPD after annealing.jpg|left|thumb|<caption>Softening ofinternally oxidizedAg/SnO₂ 88/12Pby 12 WPD after annealing for 1 hr after different degrees of cold working</caption>]]</figure>

Fig. 2.100<figure id="fig:Micro structure of Ag SnO2 92 8 PE"> Softening [[File:Micro structure of Ag SnO2 92 8 PE.jpg|left|thumb|<caption>Micro structure ofAg/SnO₂ 8892/12P8 PE: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]after annealing for 1 hr after40% cold working</figure>

Fig. 2.101<figure id="fig:Micro structure of Ag SnO2 88 12 PE"> Strain hardening [[File:Micro structure of Ag SnO2 88 12 PE.jpg|left|thumb|<caption>Micro structure ofAg/SnO₂ 88/12 WPCPE: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]by cold working</figure>

Fig. 2.102<figure id="fig:Micro structure of Ag SnO2 88 12 PW"> Softening [[File:Micro structure of Ag SnO2 88 12 PW.jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 88/12 WPC after annealingSPW: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]for 1 hr after different degrees of cold working</figure>

Fig. 2.103<figure id="fig:Micro structure of Ag SnO2 88 12 TOS F"> Strain hardening [[File:Micro structure of Ag SnO2 88 12 TOS F.jpg|left|thumb|<caption>Micro structure ofAg/SnO₂ 8688/12 TOS F: a) perpendicular to extrusion direction b) parallel to extrusion direction</14 WPCcaption>]]by cold working</figure>

Fig. 2.104<figure id="fig:Micro structure of Ag SnO2 92 8 WTOS F"> Softening [[File:Micro structure of Ag SnO2 92 8 WTOS F.jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 8692/14 WPC after annealing8 WTOS F: a) perpendicular to extrusion direction b) parallel to extrusion direction,1) AgSnO2 contact layer, 2) Ag backing layer</caption>]]for 1 hr after different degrees of cold working</figure>

Fig. 2.105<figure id="fig:Micro structure of Ag SnO2 88 12 WPD"> Strain hardening [[File:Micro structure of Ag SnO2 88 12 WPD.jpg|left|thumb|<caption>Micro structure ofAg/SnO₂ 88/12 WPD: parallel to extrusion direction 1) AgSnO2 contact layer, 2) Ag backing layer</caption>]]by cold working</figure>

Fig. 2.106:Softening of Ag/SnO<subdiv class="clear">2</subdiv> 88/12 WPD afterannealing for 1 hr after different degreesof cold working

Fig<figtable id="tab:Physical Properties of Powder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process"><caption>'''<!--Table 2. 27:-->Physical Properties of Powder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process'''</caption><table class="twocolortable"><tr><th rowspan="2"><p class="s11">Material</p><p class="s11"></p></th><th rowspan="2"><p class="s11">Additives</p></th><th rowspan="2"><p class="s11">Density</p><p class="s11">[ g/cm³]</p></th><th rowspan="2"><p class="s11">Electrical</p><p class="s11">Resistivity</p><p class="s11">[µ<span class="s14">S ·</span>cm]</p></th><th colspan="2"><p class="s11">Electrical</p><p class="s11">Conductivity</p></th><th rowspan="2"><p class="s11">Vickers</p><p class="s11">Hardness</p><p class="s11">HV 10.107:</p></th></tr>Strain hardening of<tr><th><p class="s11">[%IACS]</p></th><th><p>[MS/m]</p></th></tr>Ag<tr><td><p class="s11">AgCdO 90/10</p><p class="s11"></p></td><td/><td><p class="s11">10.1</p></td><td><p class="s11">2.08</p></td><td><p class="s12">83</p></td><td><p class="s12">48</p></td><td><p class="s11">60</p></td></tr><tr><td><p class="s11">AgCdO 85/15 </p></td><td/><td><p class="s11">9.9</p></td><td><p class="s11">2.27</p></td><td><p class="s12">76</p></td><td><p class="s12">44</p></td><td><p class="s11">65</p></td></tr><tr><td><p class="s11">AgSnO₂ 90/10</p></td><td><p class="s11">CuO and</p><p class="s11">Bi₂ O₃</p></td><td><p class="s11">9.8</p></td><td><p class="s11">2.22</p></td><td><p class="s12">78</p></SnOtd><td><p class="s12">45</p></td><td><p class="s11">55</p></td></tr><tr><td><p class="s11">AgSnO₂ 88/12 WPX</p></td><td><p class="s11">CuO and</p><p class="s11">Bi₂ O₃</p></td><td><p class="s11">9.6</p></td><td><p class="s11">2.63</p></td><td><p class="s12">66</p></td><td><p class="s12">38</p></td><td><p class="s11">60</p></td></tr></table>Form of Support: formed parts, stamped parts, contact tipsby cold working</figtable>

Fig*'''Silver–zinc oxide materials'''Silver zinc oxide contact materials with mostly 6 - 10 wt% oxide content, including other small metal oxides, are produced exclusively by powder metallurgy [[#figures1|(Figs. 58 – 63)]]<!--(Table 2.109: Micro structure of 28)-->. Adding WO₃ or Ag₂WO₄ in the process - as described in the preceding chapter on Ag/SnO₂ 92- has proven most effective for applications in AC relays, wiring devices, and appliance controls. Just like with the other Ag metal oxide materials, semi-finished materials in strip and wire form are used to manufacture contact tips and rivets. Because of their high resistance against welding and arc erosion Ag/8 PEZnO materials present an economic alternative to Cd free Ag-tin oxide contact materials (<xr id="tab: aContact and Switching Properties of Silver–Metal Oxide Materials"/><!--(Tab. 2.30) perpendicular to extrusion directionb--> and <xr id="tab:Application Examples of Silver–Metal Oxide Materials"/>)<!--(Tab. 2.31) parallel to extrusion direction-->.

Fig<figtable id="tab:tab2. 28"><caption>'''<!--Table 2.11128: Micro structure --> Physical and Mechanical Properties as well as Manufacturing Processes and Forms of Supply of Ag/SnO<sub>2Extruded Silver-Zinc Oxide Contact'''</subcaption> 88/12 PW: a) perpendicular to extrusion directionb) parallel to extrusion direction

Fig{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Additives!Density<br />[g/cm³]!Electrical<br />Resistivity<br />[μΩ·cm]!colspan="2" style="text-align:center"|Electrical<br />Conductivity<br />[% IACS] [MS/m]!Vickers<br />Hardness<br />Hv1!Tensile<br />Strength<br />[MPa]!Elongation<br />(soft annealed)<br />A[%]min. !Manufacturing<br />Process!Form of<br />Supply|-|Ag/ZnO 92/8P<br />|91 - 93||9.8|2.112: Micro structure of 22|78|45|60 - 95|220 - 350|25|Powder Metallurgy<br />a) indiv. powders|1|-|Ag/SnOZnO 92/8PW25<br />|91 - 93|Ag₂ 98WO₄|9.6|2 PX: .08|83|48|65 - 105|230 - 340|25|Powder Metallurgy<br />c) coated|1|-|Ag/ZnO 90/10PW25<br />|89 - 91|Ag₂WO₄|9.6|2.17|79|46|65 - 100|230 - 350|20|Powder Metallurgy<br />c) coated|1|-|Ag/ZnO 92/8WP<br />|91 - 93||9.8|2.0|86|50|60 - 95|||Powder Metallurgy<br />with Ag backing a) perpendicular to extrusion directionindivid.|2|-|Ag/ZnO 92/8WPW25<br />|91 - 93|Ag₂WO₄|9.6|2.08|83|48|65 - 105|||Powder Metallurgy<br />c) coated|2|-|Ag/ZnO 90/10WPW25<br />|89 - 91b|Ag₂WO₄|9.6|2.7|79|46|65 - 110|||Powder Metallurgy<br />c) parallel to extrusion directioncoated|2|}</figtable>

Fig. 1 = Wires, Rods, Contact rivets, 2.113: Micro structure of Ag/SnO₂ 92/8 PX: a) perpendicular to extrusion directionb) parallel to extrusion direction= Strips, Profiles, Contact tips

Fig. 2.115<div class="multiple-images"><figure id="fig:Strain hardening of Ag ZnO 92 8 PW25"> [[File: Micro structure Strain hardening of Ag/SnOZnO 92 8 PW25.jpg|left|thumb|<subcaption>2Strain hardening of Ag/ZnO 92/8 PW25 by cold working</subcaption> 86/14 WPC: a) perpendicular to extrusion direction]]b) parallel to extrusion direction, 1) AgSnO<sub>2</subfigure> contact layer, 2) Ag backing layer

Fig. 2.116<figure id="fig:Softening of Ag ZnO 92 8 PW25"> [[File: Micro structure Softening of Ag/SnOZnO 92 8 PW25.jpg|left|thumb|<subcaption>2<Softening of Ag/sub> ZnO 92/8 WTOS F: a) perpendicular to extrusion directionb) parallel to extrusion direction,PW25 after annealing for 1) AgSnOhr after 30% cold working<sub/caption>2]]</subfigure> contact layer, 2) Ag backing layer

Fig. 2.117<figure id="fig: Micro structure Strain hardening ofAg ZnO 92 8 WPW25"> [[File:Strain hardening of Ag/SnOZnO 92 8 WPW25.jpg|left|thumb|<subcaption>2Strain hardening of Ag/ZnO 92/8 WPW25 by cold working</subcaption> 88/12 WPD: parallel to extrusion direction]]1) AgSnO<sub>2</subfigure> contact layer, 2) Ag backing layer

Fig. 2.118<figure id="fig: Micro structure Softening ofAg ZnO 92 8 WPW25"> [[File:Softening of Ag/SnOZnO 92 8 WPW25.jpg|left|thumb|<subcaption>2Softening of Ag/ZnO 92/8 WPW25 after annealing for 1hr after different degrees of cold working</subcaption> 88/12 WPX:parallel to extrusion direction]]1) AgSnO<sub>2</subfigure> contact layer, 2) Ag backing layer

Fig. 2.119<figure id="fig:Micro structure of Ag ZnO 92 8 PW25"> [[File: Micro structure of Ag/SnOZnO 92 8 Pw25.jpg|left|thumb|<subcaption>2<Micro structure of Ag/sub> 86ZnO 92/14 WPX8 PW25: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) AgSnO<sub/caption>2]]</subfigure> contact layer, 2) Ag backing layer

Table 2<figure id="fig:Micro structure of Ag ZnO 92 8 WPW25"> [[File:Micro structure of Ag ZnO 92 8 WPW25.27jpg|right|thumb|<caption>Micro structure of Ag/ZnO 92/8 WPW25: Physical Properties of Powder Metallurgical Silver-Metal Oxide Materialsa) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/ZnO contact layer, 2) Ag backing layer</caption>]]</figure></div>with Fine Silver Backing Produced by the Press-Sinter-Repress Process<div class="clear"></div>

<figtable id="tab:tab2.29"><caption>'''<!--Table 2.2829: Physical and Mechanical -->Optimizing of Silver–Tin Oxide Materials Regarding their Switching Properties as well as Manufacturing Processes andForming Behavior'''</caption><table class="twocolortable">Forms of Supply of Extruded Silver<tr><th><p class="s12">Material/</p><p class="s12">Material Group</p></th><th><p class="s12">Special Properties<th colspan="2"></p></th></tr><tr><td><p class="s12">Ag/SnO₂ PE</p></td><td><p class="s12">Especially suitable for automotive relays</p><p class="s12">(lamp loads)</p></td><td><p class="s12">Good formability (contact rivets)</p></td></tr><tr><td><p class="s12">Ag/SnO₂ TOS F</p></td><td><p class="s12">Especially suited for high inductive</p><p class="s12">DC loads</p></td><td><p class="s12">Very good formability (contact rivets)</p></td></tr><tr><td><p class="s12">Ag/SnO₂ WPD</p></td><td><p class="s12">Especially suited for severe loads (AC-Zinc Oxide (DODURIT ZnO4) Contact</p><p class="s12">and high switching currents</p></td><td/></tr><tr><td><p class="s12">Ag/SnO₂ W TOS F</p></td><td><p class="s12">Especially suitable for high inductive DC</p><p class="s12">loads</p></td><td/></tr></table></figtable>

Fig. <figtable id="tab:Contact and Switching Properties of Silver–Metal Oxide Materials"><caption>'''<!--Table 2.12130: Softening -->Contact and Switching Properties of Ag/ZnO 92Silver–Metal Oxide Materials'''</8 PW25after annealing for 1 hr after 30% cold workingcaption>

Fig. {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Properties|-|Ag/SnO_{2.122: Strain hardening}<br />|Environmentally friendly materials,<br />Very high resistance against welding during current-on-switching,<br />Weld resistance increases with higher oxide contents,<br />Low and stable contact resistance over the life of the device and good<br />temperature rise properties through use ofspecial additives,<br />High arc erosion resistance and contact life,<br />Very low and flat material transfer during DC load switching,<br />Good arc moving and very good arc extinguishing properties|-|Ag/ZnO 92<br />|Environmentally friendly materials,<br />High resistance against welding during current-on-switching<br />(capacitor contactors),<br />Low and stable contact resistance through special oxide additives,<br />Very high arc erosion resistance at high switching currents,<br />Less favorable than Ag/SnO₂ for electrical life and material transfer,<br />With Ag₂WO<sub>4</8 WPW25sub> additive especially suitable for AC relaysby cold working|}</figtable>

Fig. <figtable id="tab:Application Examples of Silver–Metal Oxide Materials"><caption>'''<!--Table 2.11531: -->Application Examples of Silver–Metal Oxide Materials'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></th><th><p class="s12">Application Examples</p></th></tr><tr><td><p class="s12">Ag/SnO₂<span class="s48"></span></p></td><td><p class="s12">Micro structure of switches, Network relays, Automotive relays, Appliance switches,</p><p class="s12">Main switches, contactors, Fault current protection relays (paired against</p><p class="s12">Ag/C), (Main) Power switches</p></td></tr><tr><td><p class="s12">Ag/ZnO 92</p></td><td><p class="s12">Wiring devices, AC relays, Appliance switches, Motor-protective circuit</p><p class="s12">breakers (paired with Ag/8 Pw25: aNi or Ag/C), Fault current circuit breakers paired againct Ag/C, (Main) perpendicular to extrusion directionPower switches</p></td></tr></table>b) parallel to extrusion direction</figtable>

Fig====Silver–Graphite Materials====Ag/C contact materials are usually produced by powder metallurgy with graphite contents of 2 – 6 wt% (<xr id="tab:tab2. 32"/>)<!--(Table 2.116: Micro structure 32)-->. The earlier typical manufacturing process of Ag/ZnO 92/8 WPW25:asingle pressed tips by pressing - sintering - repressing (PSR) perpendicular to has been replaced in Europe for quite some time by extrusion directionb) parallel . In North America and some other regions however the PSR process is still used to extrusion direction, 1) Ag/ZnO contact layer, 2) Ag backing layersome extend mainly for cost reasons.

Table The extrusion of sintered billets is now the dominant manufacturing method for semi-finished AgC materials<!--[[#figures3|(Figs. 64 – 67)]]<!--(Figs. 2.126 – 2.129)-->. The hot extrusion process results in a high density material with graphite particles stretched and oriented in the extrusion direction [[#figures4|(Figs. 68 – 71)]]<!--(Figs. 2.29130 – 2.133)-->. Depending on the extrusion method in either rod or strip form, the graphite particles can be oriented in the finished contact tips perpendicular or parallel to the switching contact surface (<xr id="fig: Optimizing Micro structure of Silver–Tin Oxide Materials Regarding their SwitchingProperties Ag C 95 5"/><!--(Fig. 2.131)--> and Forming Behavior<xr id="fig:Micro structure of Ag C 96 4 D"/>)<!--(Fig. 2.132)-->.

Table 2Since the graphite particles in the Ag matrix of Ag/C materials prevent contact tips from directly being welded or brazed, a graphite free bottom layer is required.30: Contact and Switching Properties This is achieved by burning out (de-graphitizing) the graphite selectively on one side of Silver–Metal Oxide Materialsthe tips.

Table 2Ag/C contact materials exhibit on the one hand an extremely high resistance to contact welding but on the other have a low arc erosion resistance.31: Application Examples This is caused by the reaction of Silver–Metal Oxide Materialsgraphite with the oxygen in the surrounding atmosphere at the high temperatures created by the arcing. The weld resistance is especially high for materials with the graphite particle orientation parallel to the arcing contact surface. Since the contact surface after arcing consists of pure silver, the contact resistance stays consistantly low during the electrical life of the contact parts.

====Silver–Graphite (GRAPHOR)-Materials====A disadvantage of the Ag/C (GRAPHOR) contact materials are usually produced by powder metallurgyis their rather high erosion rate. In materials with parallel graphite contents orientation this can be improved, if a part of 2 – 5 wt% ''the graphite is incorporated into the material (Table 2.32Ag/C DF)''. The earlier typicalmanufacturing process in the form of fibers (<xr id="fig:Micro structure of single pressed tips by pressing Ag C DF"/>)<!- sintering - repressing(PSRFig. 2.133) has been replaced in Europe for quite some time -->. The weld resistance is determined by extrusion. In NorthAmerica and some other regions however the PSR process is still used to someextend mainly for cost reasonstotal content of graphite particles.

The extrusion Ag/C tips with vertical graphite particle orientation are produced in a specific sequence: Extrusion to rods, cutting of double thickness tips, burning out of sintered billets is now the dominant manufacturing method graphite to a controlled layer thickness, and a second cutting to single tips. Such contact tips are especially well suited forsemi-finished AgC materials ''(Figs. 2.126 – 2.129)''. The hot extrusion processresults in applications which require both, a high density material with graphite particles stretched weld resistance and oriented inthe extrusion direction ''a sufficiently high arc erosion resistance (Figs<xr id="tab:tab2. 33"/>)<!--(Table 2.130 – 2.13333)''-->. Depending on the extrusionmethod in either rod or strip form the graphite particles can be oriented in thefinished contact For attachment of Ag/C tips perpendicular (GRAPHOR) or parallel (GRAPHOR D) to theswitching contact surface ''(Figs. 2.131 welding and 2.132)''brazing techniques are applied.

Since Welding the actual process depends on the material's graphite particles in the Ag matrix of orientation. For Ag/C materials prevent contacttips from directly being welded or brazed, a with vertical graphite free bottom layer isrequiredorientation the contacts are assembled with single tips. This For parallel orientation a more economical attachment starting with contact material in strip or profile tape form is achieved by either burning out (de-graphitizing) used in integrated stamping and welding operations with the tape fed into the weld station, cut off to tip form and then welded to the carrier material before forming the graphiteselectively on one side of final contact assembly part. For special low energy welding, the tips or by compound extrusion of a Ag/C billetcovered profile tapes can be pre-coated with a fine silver shellthin layer of high temperature brazing alloys such as CuAgP.

In a rather limited way, Ag/C contact materials exhibit on the one hand an extremely high resistance tocontact welding but on the other have a low arc erosion resistance. This iscaused by the reaction of with 2 – 3 wt% graphite with the oxygen can be produced in the surroundingatmosphere at the high temperatures created by the arcing. The weld resistanceis especially high for materials wire form and headed into contact rivet shape with the graphite particle orientation parallel to thearcing contact surface. Since the contact surface after arcing consists of puresilver the contact resistance stays consistently low during the electrical life of thecontact partshead deformation ratios.

A disadvantage of the The main applications for Ag/C materials are protective switching devices such as miniature molded case circuit breakers, motor-protective circuit breakers, and fault current circuit breakers, where during short circuit failures, highest resistance against welding is their rather high erosion raterequired (<xr id="tab:tab2. In materialswith parallel graphite orientation this can be improved if part of the graphite isincorporated into the material in the form of fibers (GRAPHOR DF34"/>), ''<!--(Fig. Table 2.13334)''-->.The weld For higher currents the low arc erosion resistance of Ag/C is determined compensated by the total content of graphite particlesasymmetrical pairing with more erosion resistant materials such as Ag/Ni, Ag/W and Ag/WC.

<div class="multiple-images"><figure id="fig:Strain hardening of Ag/C tips with vertical graphite particle orientation are produced in a specific96 4 D">sequence[[File: Extrusion to rods, cutting Strain hardening of double thickness tips, burning out ofgraphite to a controlled layer thickness, and a second cutting to single tips.Such contact tips are especially well suited for applications which require both,a high weld resistance and a sufficiently high arc erosion resistance ''(Table 2Ag C 96 4 D.33)''.For attachment jpg|left|thumb|<caption>Strain hardening of Ag/C tips welding and brazing techniques are applied.96/4 by cold working</caption>]]</figure>

welding the actual process depends on the material's graphite orientation. For<figure id="fig:Softening of Ag C 96 4 D"> [[File:Softening of Ag/C tips with vertical graphite orientation the contacts are assembled withsingle tips96 4 D. For parallel orientation a more economical attachment starting withcontact material in strip or profile tape form is used in integrated stamping andwelding operations with the tape fed into the weld station, cut off to tip form andthen welded to the carrier material before forming the final contact assemblypart. For special low energy welding the jpg|left|thumb|<caption>Softening of Ag/C profile tapes GRAPHOR D and DF96/4 after annealing</caption>]]can be pre-coated with a thin layer of high temperature brazing alloys such asCuAgP.</figure>

In a rather limited way, <figure id="fig:Strain hardening of Ag C DF"> [[File:Strain hardening of Ag C DF.jpg|left|thumb|<caption>Strain hardening of Ag/C with 2 – 3 wt% graphite can be produced in wireDF by cold working</caption>]]form and headed into contact rivet shape with low head deformation ratios.</figure>

The main applications for <figure id="fig:Softening of Ag/C materials are protective switching devices suchDF after annealing"> as miniature molded case circuit breakers, motor-protective circuit breakers,and fault current circuit breakers, where during short circuit failures highestresistance against welding is required ''(Table 2.34)''[[File:Softening of Ag C DF after annealing. For higher currents the lowarc erosion resistance jpg|left|thumb|<caption>Softening of Ag/C is compensated by asymmetrical pairing withDF after annealing</caption>]]more erosion resistant materials such as Ag</Ni and Ag/W.figure>

Fig. 2.126<figure id="fig:Micro structure of Ag C 97 3"> Strain hardening[[File:Micro structure of Ag C 97 3.jpg|left|thumb|<caption>Micro structure of Ag/C 9697/3: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</4 Dcaption>]]by cold working</figure>

Fig. 2.127<figure id="fig:Micro structure of Ag C 95 5"> Softening [[File:Micro structure of Ag C 95 5.jpg|left|thumb|<caption>Micro structure of Ag/C 9695/4 D after5: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</caption>]]annealing</figure>

Fig. 2.128<figure id="fig: Strain hardeningMicro structure of Ag C 96 4 D"> [[File:Micro structure of Ag C 96 4 D.jpg|left|thumb|<caption>Micro structure of Ag/C DF by cold working96/4: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</caption>]]</figure>

Fig. 2.129<figure id="fig: SofteningMicro structure of Ag C DF"> [[File:Micro structure of Ag C DF.jpg|left|thumb|<caption>Micro structure of Ag/C DF after annealing: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag/Ni 90/10 backing layer</caption>]]</figure></div><div class="clear"></div>

Fig<figtable id="tab:tab2. 32"><caption>'''<!--Table 2.13032: Micro structure -->Physical Properties of Ag/C 97Silver–Graphite Contact Materials'''</3: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layercaption>

Fig{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Density<br />[g/cm³]!Melting Point<br />[°C]!Electrical Resistivity<br />[μΩ·cm]!colspan="2" style="text-align:center"|Electrical<br />Conductivity<br />[% IACS] [MS/m]!Vickers-Hardnes<br />HV10<br />42 - 45|-|Ag/C 98/2|97. 25 - 98.5|9.5|960|1.85 - 1.131: Micro structure of 92|90 - 93|48 - 50|42 - 44|-|Ag/C 9597/3|96.5 - 97.5: a) perpendicular to extrusion directionb) parallel to extrusion direction, |9.1|960|1) .92 - 2.0|86 - 90|45 - 48|41 - 43|-|Ag/C contact layer, 96/4|95.5 - 96.5|8.7|960|2.04 - 2) .13|81 - 84|42 - 46|40 - 42|-|Ag backing layer/C 95/5|94.5 - 95.5|8.5|960|2.12 - 2.22|78 - 81|40 - 44|40 - 60|-|AgC DF<br />GRAPHOR DF[[#text-reference1|¹]]|95.7 - 96.7|8.7 - 8.9|960|2.27 - 2.50|69 - 76|40 - 44|-|}<div id="text-reference1">₁ Graphite content 3.8 wt%, Graphite particles and fibers parallel to switching surface</div></figtable>

<figtable id="tab:tab2.33"><caption>'''<!--Table 2.33: -->Contact and Switching properties of Silver–Graphite (GRAPHOR) Contact Materials'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></p></th><th><p class="s11">Properties</p></th></tr><tr><td><p class="s12">Ag/C</p></p></td><td><p class="s12">Highest resistance against welding during make operations at high currents,</p><p class="s12">High resistance against welding of closed contacts during short circuit,</p><p class="s12">Increase of weld resistance with higher graphite contents, Low contact resistance,</p><p class="s12">Low arc erosion resistance, especially during break operations, Higher arc erosion with increasing graphite contents, at the same time carbon build-up on switching chamber walls increases, silver-graphite with vertical orientation has better arc erosion resistance, parallel orientation has better weld resistance,</p><p class="s12">Limited arc moving properties, therefore paired with other materials,</p><p class="s12">Limited formability,</p><p class="s12">Can be welded and brazed with decarbonized backing, GRAPHOR DF is optimized for arc erosion resistance and weld resistance</p></td></tr></table></figtable>

Pre<figtable id="tab:tab2.34"><caption>'''<!--Table 2.34:--Production >Application Examples and Forms of Supply of Silver– Graphite Contact Materials'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p><p class="s12"></p></th><th><p class="s12">Application Examples</p></th><th><p class="s12">Form of Supply</p></th></tr><td><p class="s12">Ag/C 98/2</p><p class="s12"></p></td><td><p class="s12">Motor circuit breakers, paired with Ag/Ni</p></td><td><p class="s12">Contact tips, brazed and welded contact parts, some contact rivets </p><p class="s12">Contact profiles (Bildweld tapes), Contact tips, brazed and welded contact parts</p></td></tr><tr><td><p class="s12">Ag/C 97/3</p><p class="s12"></p><p class="s12">Ag/C 96/4</p><p class="s12"></p><p class="s12">Ag/C 95/5</p><p class="s12"></p><p class="s12">Ag/C DF</p></td><td><p class="s12">Circuit breakers, paired with Cu, Motor-protective circuit breakers, paired with Ag/Ni,</p><p class="s12">Fault current circuit breakers, paired with Ag/Ni, Ag/W, Ag/WC, Ag/SnO₂<span class="s45"></span>, Ag/ZnO,</p><p class="s12">(Main) Power switches, paired with Ag/Ni, Ag/W</p></td><td><p class="s12">Contact tips, brazed and welded contact</p><p class="s12">parts, some contact rivets with</p><p class="s12">Ag/C97/3</p></td></tr></table></figtable>